Core drilling and extracting device



June 4, 1929. E. SMITH CORE DRILLING ANDEEIXTRACTING DEVICE Filed Oct.192 4 2 Sheets-Sheet l INVENTOR Zyy/m/an JmzZ/a ATTORNEYS June 4, 1929.E. SMITH CORE DRILLING AND EXTRACTING DEVICE Filed Oct. 9, 1924 2Sheets-Sheet 2,

lill'itilt IIIII! g nwna? llm INVENTOR 12731661072 6777215.

ATTORNEYS UNITEDSTATES PATENT eerie-a;

drives the rotating Pateiited June 4, 1929;

neerns'roiv SMITH, or MAMAnoNncK, NEW YORK, assrenoa 'ro EGGLESTONDRILL- me coaronarron, or novnn, DELAWARE, ACORPORATION or DELAWARE.

cons: DRILLING AND nx'mnorme Device.

Application filed October 9, 1924. Serial No, 742,521.

This invention relates to the drilling of wells for oil, gas, water,minerals, and the like, and more particularly to' devices for drillingand extracting cores so as to obtainwith facility samples of the rockorother materialbeing drilled through. The object of the invention isthe provision of an improved core drilling and extracting device.

In obtaining cores during .well drilling of this character a drillingbit which cuts its way through the tion is employed, nular in form socentral opening in the drilling bit being anthe bit is left uncut; Afterthe drilling has progressed a short distance, the uncut portion of therock projects upwardly through the annular bit in the form of a core.When an annular hole has been drilled in this manner to a depthsufiicient to produce a core varying from a few inches to several feetin length, the core is broken off :and removed from the hole by anappropriate core-taking device.

The core-taking or extracting device is lowered on a cable into thedrill stem which bit, and it is sometimes difficult properly tomanipulate the corecatcher when it is run into the hole after the corehas been cut and break off and recover the core. In the utilization ofthe automatic bit feed of myinvention disclosed and claimed in myapplication Serial No; 712,197, filed May 10, 1924, it might bedifficult in "some cases to recover cores in this manner. 3

Hence, it is desirable to have the core-extracting device in positionwithin the drill stem during the drilling of the core so that the corewill enter the removing device after it is cut. In order to operate thedrilling apparatus in this manner with the core-taking device inposition during the drilling operation, it is desirable, if notnecessary, to

provide automatic means for detaching the cable after the core-takingdevice has been placed in operating position so as to permit the cableto be hoisted out of the drive pipe and the surface end of this pipe tobe conrock by a motion of rotathat the rock opposite the the same timesupporting gage the core so I nected to a source of'water pressure forsupplying water to the cutting surfaces of the drilling bit Likewise,automatic means must be provided to the core-taking been cut. y

In constructing a core drilling and extracting device of this type, itis important that Y the latching and tripping mechanism for detachingand attaching the cable be arranged device after the core has to operatewith an extremely high degree of safety, for if the core-taking devicewere allowed to fall a distance of several hundred or several thousandfeet, great damage would be done to the hole. In fact, such an accidentis capable of damaging the hole to 6 such an extent that it is necessaryto sidecut around the damaged portion, or. even abandon the holealtogether.

The core barrel should remain stationary with the core, and hence thedrill stem must rotate with respect to the core barrel. The frictionbetween these parts should be reduced as much as possible, and" adequatemeans for accomplishing this result,and at the, drill stem, should beprovided.

It is also important that the core barrel be furnished with effectivecore engaging devices by which the core may be readily broken off andwithdrawn from the hole. These devices must, therefore, positively enasto prevent any possi bility of the core itself being allowed to'fall.Moreover, Thavefound that a drilling bit constructed of abrasivematerial, such, for example, as carborundum, is particularly effectivein drilling wells when appropriate means is provided for regulating thepressure of the bitagainst the bottom of the hole. When such a bit isused it is importanit that the lower end of the core barrel be preventedfrom coming in contact with the bit, as this would cause rapid wear ofthe core barrel and might also damage the bit itself.

During the usual operation of drilling a well it is frequently desirableto drill con- .siderable lengths of the hole without taking forreattaching the cable the core barrel by 75 the cores. In order tochange from an annular bit to a solid bit it is customary to remove theentire drive pipe from the hole. This necessitates taking apart thedrive pipe section by section and then replacing it in a similar manner,which requires an unreasonable amount of time.

In accordance with my present invention I provide the core barrel, thatis, the core extracting device, with" a releasable bail for lowering itinto operative position within the drill stem, andI also provide meansoperable upon the core barrel reaching the operative position forreleasing the bail. That is, the bail-releasing'means is actuated onlyby thefinal movement of the core barrel to its final operative position.There is, therefore, -no possibility of the bail-releasing means beingtripped as the core barrel is being lowered into the hole. Thus thedanger of the core barrel being tripped while near the surface, whichwould result in the wrecking of the bottom of the hole, is eliminated. Alifting bail is also provided which, when lowered into the drill stemafter the core has been cut, positively engages the core barrel in sucha manner that it is impossible to disengage these parts automatically,but to do this the core barrel must be hoisted to the surface and thelifting bail disengaged by hand.

The mechanism which I employ for accomplishing these results comprises alatch member which is secured to the core barrel and which is biased toagiven position. In its normal position this latch member is adapted toengage the lowering bail, but when the core-barrel moves into its finaloperative position within the drill stem, the latrh member is moved bymeans disposed at this operative. position and preferably upon the drillstem into a position of disengagement with the lowering bail which maythen be hoisted out of the hole. .The latch member is held in thedisengaged positionas long as the core barrel is in its operativeposition, and when it is desired to remove the core barrel a liftingbail is lowered into the hole which engages the latch. member in theposition in which it is held, and when once the lifting bail has beenthus interlocked with the core barrel, it is imossible to detach ituntil the core barrel" iias been hoisted to the surface.

The invention also involves the provision of a friction reducing bearingfor supporting the core barrel within the drill stem, and core engagingdevices hinged at their lower ends to the core barrelso that they fallby gravity against the core, each of these devices having a plurality ofteeth which are disposed along a curve so that one or more of the teethare presented to the core at every possible angular position, of thesedevices. In addition, means is provided for guiding the lower end of thecore barrel into alignment with the annular hole in the drilling bit soas to prevent damageto thebit or to the core barrel during the drillingoperation. Furthermore, in order to provide for the drilling of completeholes without leaving a core, an'inner cutting member of abrasivematerial is secured to a mounting which is provided with the latchmechanism of my invention and lowered into the drill stem in place ofthe core barrel. This inner cutting member rests upon an annularshoulder on the annular abrasive bit and is driven by the frictionbetween these engaging surfaces. It has a passage for drilling waterextending through it longitudinally and this passage is eccentricallyarranged so that a complete hole will be cut. A better understanding ofthe invention will be had by referring to the accompanying drawingswhich illustrate, by Way of ex- .ample, a mechanical embodiment of theinvention. In these drawings:

Fig. 1 is a longitudinal section of the core drilling and extractingdevice showing the core barrel supported by the lowering bail just abovethe operative position;

Fig. 2 is a similar view showing the core barrel in operative position,the latch members being forced inwardly and having released the bail,which has been hoisted out;

Fig. 3 is a transverse section on line 33 of Fig. 1, showing the latchmembers in engagement with the lowering bail Fig. 4 is a transversesection on line 44; of Fig. 2, showing the water passages or channelsthrough the guide collar for'the lower end of the core barrel;

Fig. 5 is a similar view on line 55 of Fig. 2, showing the mounting ofthe core ongaging devices;

Fig. 6 is a longitudinal section similar to Figs. 1 and 2 showing thelifting bail lowered into engagement with the latch mem bers and lockedtherewith ready to hoist the core barrel to the surface;

. Fig. 7 is a transverse section on line 77 of Fig. 6;

Fig. 8 is a longitudinal section of the lower port-ion of the drillingapparatus sl'iowing the inner cutting member and its mounting inposition within the drill stem and resting upon the annular abrasivebit; and

Fig. 9 is a transverse section taken on the line 99 of Fig. 8.

Referring to these drawings, an annular bit 10 of abrasive materialhaving a central longitudinal opening 11. is rotated to drill the hole12. The bit 10 is secured to the bit mounting 13--by means of babbitt14, and

' As is illustrated in the lower .-end of the driven same to the drivepipe by which the drilling apparatus is rotated. v

the drawings, however, the drilling apparatus is driven by the drivepipe through a slidable joint orautomatic bit feed such, for example, asis shown in my prior application above mentioned. Therefore, thecoupling 16.is threaded onto member 17 of such a slidable joint. Thedriving member of this mechanism is indicated at 18, only the -lower endbeing shown and its upper end being mounted upon the drive pipe. Members18, and 17 are connected together by means of a longitudinal key virtueofthis connection rotary motion 1s transmitted from member 18 to thedriven member 17 whilethe member 17 is at the same time allowed to'slidefreely in thever tical direction. within the member 18. By

means of this connection the weight of the A drive pipe is removed fromthe cutting bit 10 and the ap ropriate feeding pressure for enabling thea rasive bit to operate atman'imum cuttin speed can be readily applied.The core arreland in this application this term is intended to includeany form of core extractin device-cons1sts of three th i pro erpositions,

parts, a central barrel portion 20 of relatively thin metal, a dogholder '21, and a guard ring 22. The central portion 20 may e as long asnecessary to form a chamber of the required-size to accommodate thedesired length of core. The dog holder 21 is screwed onto the lower endof the barrel portion 20 and consists-of a hollow cylinder the interiordiameter of which is slightly greater than that of the opening 11 of theabrasive bit and the walls of which are relatively thick.

The core engaging devices are mounted in the dog holder 21 and, in thepreferred form, these devices comprise two or more dogs 23 which aremounted in recesses 24 in the walls of the dog holder 21, the dogs being,of substantially the same thickness as these walls. Dogs 23 are hingedat their lower ends by pins 25 which are driven into the walls of dogholder 21, as is clearly shown in Fig. 5. Each of the dogs 23 isprovided near its upstanding end with a series of relatively sharptranverse teeth 26 which are out upon a curve as indicated so that oneor more of these teeth are presented to the core in any angular positionwhich the dogs may assume. .The dogs are urged inwardl away from theirdead center position an against the core by means of flat springs 27which are rivetedwithin recesses 24.- These springs prevent the dogsfrom protruding beyond the outer surface of the dog holder and insurethat the dogs will al-' 19, and byto dig into the surface of thecore,.and by employing this form of teeth, in combina-' of the dogs attheir C tion with the hingin lower ends so that t ey are always urgedbygravity against the core, any lifting movement of the core barrel willtend to force the dogs withincreasing pressure into the core.

It is important that the dogs 23 be kept from falling below thehorizontal position because if they should be turned downwardly whilethe 'core barrel is in position to .receive a core, the dogs might.become engaged with one another so as to prevent them from Ireassuming' their upward positions and the upward pressureofthe corebeing cut would then ser ously damage the dogs. In order to obviatethis, the dogs 23 are provided withportions 23 which extend a shortdistance beyond the pins 25. The dogs may engage one another as shown inFig. 1 and prevent their falling into the downward pobutin the eventthat they do not so sition these projections 23- engage one another,Wlll come in contact with the inner surface of the annular bit 10, asshown in Fig. .1,

and the dogs willthus be maintained in that the dogs project upwardlywhile the core barrel 20 is being lowered into the well, a small blockof wood (not shown) may be inserted between the teeth of the dogs. Thisblock'will hold. the dogs in position until the core pushes it upwardlyand is engaged by the teeth of the dogs.

The guard ring'22 is threaded upon the outside of the upper end of thecentral portion 20 of the core barrel and has-around its lower end ashoulder 28 by which the core barrel is supported within the drill stem15. For this purpose a friction reducing be'ar- In order to be sure ingis employed which comprises a pair of collars 29 and 30 which have ballraces along their opposing surfaces in which the balls 31 roll.

plin 16 which is provided with a-chamber 32 a ove the end of thelower-threads 33, this chamber being slightly larger than collar 29. r

In assembling these parts collar 29 is Thesecollars are held in positioni by means of the specially constructed couplaced within the chamber 32and, collar I being between the 34, fora purpose which will appear lateri and also for engagement-with the shoulder 28 so as to support the corebarrel in OP- gi erative position. v

portion 20 of the core barrel.

The latch members by which the core barrel is lowered into. andlifted'from the operative position comprise one or more resllient oryieldably rmounted arms which are riveted at 36 to the inside of thecentral Two oppositely arran ed latch members are preferably used. heyare provided at their up per ends with hooks 37 for engaging the portion20 and have curved cam surfaces 42 for the purpose of extending throughthe slots 41 into the path of the collar 29 when the hooks 37 are intheir normal outermost position, to which they are biased by theresiliency of the latch members 35. The

latch members, however, are bent inwardly just above the ends of the camportions 42 so as to re-enter the core barrel, and the outermost partsof the cam surfaces 42 always remain within the diameter of the guardring 22 so as to be protected thereby against accidental tripping.

When a core barrel is to be lowered into operative position within thedrill stem, the bail 38 is inserted in guard ring 22 and snapped ontothe latch members 35 andlowered down the drill pipe by means of cable39. In Fig. l the core barrel has reached the bottom of the hole and isabout to move into operative position. The hooks 37, however, stillengage the annular ring 40. When the core barrel is lowered a slightdistance further, andthus passes into its final operative position, thecam surfaces 42 are engaged by the rounded shoulder 34 of collar 29 'sothat the latch members 35,are forced inwardly thereby and the hooks 37are released from engagement with annular ring 40 of the bail 38.

In Fig. 2 the core barrel has settled to its final fposition and bail 38has been hoisted out o the well so that the drive pipe may be connectedwith an appropriate drilling water supply and the drilling operationresumed. It will be noticed that in this position the outwardlyprojecting points of the latch members 35 lie against the interiorsurface of collar 29, thus holding the hooks 37 in'restricted positionas long as the core barrel remains in'its operative position.

In lowering the core barrel into position, it important that the barrelbe suitably guided and held with its axis substantially in ahgnment withthe axis of the dr' bit 10, and for this purpose an annular guide ringor collar 43 is mounted toward the lower end of drill stem 15, this ringbeing channeled, as indicated at 44, to allow for the passage ofdrilling water. The upper corner of the guide ring is chamfered at 45 soas to assist in guiding the beveled end 46 of the core barreltherethrough.

The hooks 37 of the latch members extend the bail in longitudinalalignment with the core barrel and assist inpreventing the ac cidentalreleasing of the core barrel from the bail.

In Fig. 2 drilling has progressed to a point where a core 47 projects aconsiderable distance into the core barrel, and drilling may becontinued in this way until the eore reaches a head 48 which forms theroof of the core chamber, and for this purpose is fitted tightly andsolidly to the inner walls of the central barrel portion 20. During thedrilling of the hole water is forced downwardly through the drive pipe,through the sliding joint, and guard ring 22, into the chamber of thecore barrel above head- 48. j

From this chamber it passes radially outwardly through openings 49 inthe central portion 20 into the annular spacebetween the core barrel anddrill stem 15, indicated by the arrows. The water flowing thencedownwardly goes through channels 44 in guide ring 43 and then passesinto the. narrow annular. space 50 between the lower end of the corebarreland the abrasive bit. From here the drilling water flows betweenthe core and the wall of the opening 11 of the abrasive bit to thecutting surfaces. After pass ing between the cutting'surfaces thedrilling water flows upwardly between the outside of drill stem 15 andthe walls of the hole 12. e

It is preferable to have'the lower end of the core barrel extend intoclose proximity to the upper surface of the abrasive bit 10 and evenenter a recess in the upper part of the bit, as shown in Figs. 1 and 2.Guide ring 43, however, coacts with the exterior of the core barrel insuch a manner as to prevent the core barrel from coming into contactwith the abrasive bit, inasmuch as the rotation of the bit would rapidlywear away the core barrel, and also because, if the bottom of the corebarrel should strike the abrasive bit as it is being lowered into p0-sltion, it might crack the bit or loosen it from its mounting.

While the annular hole shown in Fig. 2

is being drilled, which results in the formation of core 47, the corebarrel is held stationary by frictional engagement with the minimum offriction. Hence, the drag upon the core is relatively small, and coresmay be cut in relatively soft format ons and taken out without in ury orbreaking 'up.

As the, core 47 increases in length, the water which fills thecorechamber must be displaced and is expelled through the bell valve 51 inhead 48.

When it is desired to remove the core, the supply of drilling water iscut off and the lifting bail 52 shown in Fig. 6 is lowered down thedrive pipe by means of cable'39.

This bail is similar to the lowering bail 38, but the bail cylinder hassecured to its lower end a hollow cylinder 53 having relatlvely thickwalls and terminating at the bottom in an annular wedge-shaped head 5%having shoulders 55 for engaginghooks 37 of the latch members 35. Theupper end of guard ring 22 1s flared 1 'as shown at 56 so as tofacilitate the manual insertion of the lowering bail 38, and

particularly to coact with the wedge-shaped ead of the lifting bail 52to facilitate its entrance into the guard ring when this bail is loweredinto the well. After thehead 54 slides into and telescopes with guardring 22, its wedge-shaped surfaces also force the hooks 37 furtherinwardly into a third position from which they snap outwardly intoengagement with the shoulders 55.

The bail 52 may thus be automatically interlocked with the core barrel,and inasmuch as the outermost points of the latch mem bers 35 are heldwithin the diameter of the guard ring 22, there is no possibility oftheir becoming engagedwith an object so that the core barrel will beacci entally released from the bail. The core barrel and core may thusbe safely hauled to the surface by cable 39. As tension is applied tothe cable, the teeth 26 of dogs 23 are forced.

against the core 47 with considerable pressure, this pressure increasingas the pull on tliife cable is increased, until the core breaks 0 Whenthe core barrel is brought to the surface the core is taken out and bail52 is manually released from engagement with the latch members 35. Hitis desired to out another core immediately, lowering bail 39 is thenattached to the core barrel, and it is lowered backinto position in thedrill stem. If, however, it is not necessary to take another coreuntilthe hole has been drilled to some further depth, 'the device illustratedin Fig. 8 for drilling a complete hole instead of an annular hole isutilized.

This device'comprises an inner cutting bit 57 .also of abrasivematerialand of substantiaily the same external diameter as the core barrelpreviously taken out. The inner I cutting bit 57 is mounted by means ofbabbitt in the end of a tubular member 58 which may not necessarily beas long as the core barrel, inasmuch as it isnot supported upon the ballbearing. collar 29!. The tubular member 58, however, is provided at itsupper end with the latch members 35 and the guard, ring 22.

The member 58 and the inner cutting bit 57 may therefore be lowered intothe drill stem 15 by means of lowering bail 38 and removed by means ofthe lifting bail 52 in exactly the same manner as the core barrel wasinserted and removed.

Tubular member 58 is open at its upper end so that the drilling waterpasses down through the. cylinder and through a passageway 59 in theinner cutting bit 57 into the central opening 11 of the bit 10, and-thusto the cutting surface. Passageway 59 is preferably eccentricallydisposed so that a complete hole will be out without leaving a core.

The inner cutting bit 57 is rotated by its frictional contact with theshoulder 60 on the main annular bit 10. If it is necessary, the frictionof these surfaces may be increased by adding weight to the inner cutting bit 57, say, for example, in the form of shot within the tubularmember 58, th,e

taken with comparative ease and safety, and

when the inner cutting bit 57 i is employed in conjunction with thecore-taking device, it is possible to change over from a core drillingoperation to the. drilling of a complete hole in 'an'extremely shorttime. It is not necessary to remove the drive pipe from the hole, butmerely to hoist out the core barrel by means of a cable and in place ofthis core barrel lower into the drill stem on' the same cable the innercutting bit member. This member takes the place of the core barrel andbecause of its construction drills away the core at the same time thatthe annular bit is drilling the annular hole.

I claim: I

1. In a well drilling device the combination of, a core cutting bit, atubular drill stem therefor, a core barrel insertable within the drillstem, a latch member yieldably mounted on the core barrel and biased inone direction, a bail having means engaging the latch member in thenormal position of said member so as to lower the core barrel intooperative position within the drill stem, and means disposed at theoperative position for forcing the latch member out of engagement withthe bail'when the core barrel reaches said position.

2. In a well drilling device the combination of, a core cutting bit, atubular drill .operative position for forcing the latch member to asecond position out of engagement with. the bail when the core barrelreaches ,said position so that the bail may be removed from the drillstem, and a lifting bail, adapted to be lowered into the drill stem,having means for forcing the latch member into a third position therebyinterlocking itself therewith and affording means for withdrawing thecore barrel.

3. In a well drilling device the combination of, a core cutting bit, atubular drill stem therefor, a core barrel insertable within the drillstem and provided near its upper end with a yieldably mounted latchmember, shoulders on the drill stem and core barrel respectivelyadapted.- to ooact to support the latter in operative position, a bailfor lowering the core barrelto operative position having a shoulderedring engaginga hook on the latch member, the latch member having a camportion extending outwardly through the wall of the core barrel which isengaged by the shoulder on the drill stem when the core barrel reachesthe operative position and forces the latch member inwardly to release.the bail so that it may be removed from the drill stem, and a liftingbail, adapted to be lowered into the drill stem, having a wedge-shapedannular head for forcing the latch member further inward and engagingthe hook thereof so as to withdraw the core barrel.

4. In a well drilling device the combination of, a core cutting bit, atubular drill stem therefor, a core barrel insertable within the drillstem, a latch member on the core barrel near the upper end thereof, abail having means for engaging the latch member so as to lower the corebarrel into operative position within the drill stem, and means disposedat the operative position for coacting with the latch member when thecore barrel reaches said position so as to release the bail therefrom,said core barrel having a guard portion extending above the latch memberto protect said member. 5. In a well drilling device the combination of,a core cutting bit, a tubular drill erative position within the drillstem, and

means disposed at the operative position for coacting with the latchmember when the core barrel reaches said position so as to release thebail therefrom,- said core barrel having a guard portion extending abovethe latch member and having a flaring mouth for guiding the bail intoengagement with the latch member.

6. In a well drilling device the combination of, a core cutting bit, atubular drill stem therefor, a core barrel insertable within the drillstem, a latch; member on the core barrel near the upper end thereof, abail having means for engaging the latch member so as to lower the corebarrel into operative position withinthe drill stem, and

means disposed at theuoperative position for coacting with the latchmember when the core barrel reaches said position so as to release thebail therefrom, and a guard ring secured to the upper end of the corebarrel and extending above the latch member having a flaring mouth forguiding the bail into engagement with the latch member.

7. In a well drilling device the combination of a-core barrel having alatch member resiliently secured interiorly of the barrel below theupper end thereof, and an annular bail memberadapted to telescope withinthe end of the barrel having means to engage the latch member in thisposition.

8. In a well drilling device the combination of a core barrel having alatch member resiliently mounted interiorly of, the barrel below theupper end thereof, and a bail member having an annular pick-up portionfor telescoping within the end of the barrel,

said pick-up portion being wedge shaped at its lower end for springingsaid latch member 'into engagement therewith.

9. In a well drilling device, the combination of a core cutting bit,insertable within the drill stem, a prong-shaped latch memberresiliently mounted on the. core barrel, a bail having an annular ledgefor engaging said latch member for lowering the core barrel intooperative position within the drill stem, and an annular ring carried bya friction reducing bearing upon the interior wall of the drill stem andprojecting in wardly therefrom a sufficient distance to force said latchmembers out of contact with said annular ledge when the core barrelreaches the o erative position so as to release .the bail therefrom.

10. In a well drilling device, the combination of a core cutting bit, atubular drill stem therefor, a core barrel insertable within the drillstem, a prong-shaped latch member resiliently mounted on the core barrela bail lease the bail therefrom, and a second bail having an annularledge for engaging said having an annular wedge shaped lower end latchmember for lowering the core barrel and an annular ledge thereabove bywhich into operative position within the drill stem, said latch memberis forced inwardly and I 5 an annular ring mounted upon, a frictionengaged when this second bail is lowered 15 reducing bearing within thedrill stem and into the drill stem to pick up and withdraw projectinginwardly a sufficient distance to the core barrel.

force said latch member out of contact with In testimony whereof I aflixmy signature. said annular ledge when the core barrel 10 reaches theoperative position so as to re- EGGLESTON SMITH.

